Alloys for addition to iron and steel



Patented Dec. 6, 1938 PATENT OFFICE 2,139,515 I ALLOYS roe ADDITION 'romos AND STEEL George L. Norris, Scarsdale, N. Y., assignor to VanadiumCorporation oi America, Bridgeville, Pa., a. corporation oi Delaware NoDrawing. Application April 25, 1938, Serial 3 Claims. (01. 75-58) Thisinvention relates to an alloy containing Per cent silicon, titanium,zirconium, and iron, and esp- Silicon" V 40.28 cially to an alloysuitable for addition to molten Titanium 10.62 iron and steel for thepurpose of obtaining a Zirconium 10.49

5 more sound, dense and clean metal when such Carbon 0.07 steel or ironsolidifies. Aluminum 1.53

The present application is a continuatiomm- Manganese 0.76

part of my copending application, Serial No. Iron Balance 128,230, filedFebruary 27, 1937.

The use of ferro-silicon, form-titanium, ferrozirconium,iron-silicon-zirconium, and ironsilicon-titanium for the purpose ofscavenging molten steel and iron is very well-known and is more or lessgenerally employed in steel and iron 15 manufacturing practice. Theiruse, however, in-

volves very marked deficiencies so that, while they free the moltenmetal of impurities, such as iron oxide and iron nitride by chemicallyreacting with these compounds, the products: iron silill cates, titaniumcyanonitrides, and zirconium cyanonitrides, remain entrapped in themetal, thereby imparting to it several objectionable qualities. Theamount of non-metallicsremaina ing entrapped in the metal is not alwaysthe 85 same. Therefore, iron and steel alloys are obtained which havevarying physical qualities,

such as ductility, although of the same chemical composition. 1 I havediscovered that, the combination of all 80 three elements-silicon,titanium and zirconium --with iron, in proper proportions, produces analloy which when added to molten iron and steel reacts with; gaseous andother impurities in the molten metals to form reaction products I5 whichmore readily coagulate and separate from the molten iron or steel. Myalloy is readily soluble in molten iron or steel andis more efiectlveand economical than alloys containing only oneor two of the elementssilicon, titanium 40 and zirconium in combination with iron.

My alloy not only acts as a scavenger in molten iron and steel, 1. e.,removes the various impuritiesin the molten metal but also serves tocontrol the grain size of the treated product. 45; While my alloy iscomposed of silicon, titanium, zirconium and iron and is substantiallyfree from 'carbon, there may be present small percentages of otherelements incidental to'the method of production. or inv the rawmaterials used. .For example, the chemical composition or one melt ofthis alloy which may be considered typical in respect to the presence orthe other metals, is:

vention consists of an alloy with a minimum amount of carboni-so as tobe substantially free from carbon, and contains about 25% to 60%silicon, preferably about 25% to 45% silicon, about 5% to or titanium,and about 5% to 20% or 25% zirconium. In no case, however, does the sumof the silicon, titanium and zirconium exceed 85%. The percentage ofsilicon is at least equal to or greater than the percentage of eitherthe titanium or zirconium. The remainder of the alloy is principallyiron, although usual impurities or small amounts of other alloyingelements may be present.

While I have described my alloy in its preferred composition, it is tobe understood that the invention is not so limited, but may be otherwiseembodied withln the scope of the following claims.

I claim:

1. An alloy for addition to iron and steel, containing about 25% to 60%silicon, about 5% to 25% titanium, about 5% to 25% zirconium, the sum ofthe silicon, titanium and zirconium not exceeding 85%, and not overabout 4.0% carbon, the remainder being principally iron.

2. An alloy for addition to iron and steel, containing about 25% to 60%silicon, about 5% to 25% titanium, about 5% to 25% zirconium, the sum ofthe silicon, titanium and zirconium not exceeding 85%, and not overabout 1.0% carbo the remainder being principally iron.

3. An'alloy for addition to iron and steeLcontaining about 25% to 45%silicon, about 5% to 20% tianium, about 5% to 20% zirconium, and notover about 0.15% carbon, the remainder being principally iron.

GEORGE L. NORRIS.

